The present invention concerns a process for evaluating signals from an incremental generator. An incremental generator is a component employed to digitally operate controls. It consists, for example, of a pulse generator in the form of a disk with a series of alternately optically and mechanically sensed indications on it that emit pulses when the component is activated, by rotating the disk for example. To make it possible to detect the direction that the disk is rotating in, the indications are radially displaced, such that two phase-shifted signals, in the form of square pulses for example, can be obtained at two output terminals of the generator. The direction that the disk is rotating in can then be detected by the phase of the two signals emerging from the generator. The pulses from one output terminal are employed to incrementally adjust controls that emit a control voltage that can be discontinuously varied higher or lower. The series of pulses obtained from the generator are processed such that every positive edge, for example, will vary a control parameter up or down to a prescribed extent.
Simple incremental generators, however, involve the drawback that the pulses they emit have noise at their edges that occurs when the equipment is jolted for example. The result is, for example, that every positive edge will vary one increment, that the controls will accordingly be varied to different extents even though the generator is set constant, and that several increments forward or backward for example will be processed even though only one pulse should have been generated and the generator is to be adjusted in only one direction.